Merge pull request #7357 from paritytech/unwrap-or

Avoid using ok_or with allocated argument

ethcore/src/engines/validator_set/contract.rs

@@ -58,7 +58,7 @@ impl ValidatorContract {
 		let client = self.client.read().clone();
 		Box::new(move |a, d| client.as_ref()
 			.and_then(Weak::upgrade)
-			.ok_or("No client!".into())
+			.ok_or_else(|| "No client!".into())
 			.and_then(|c| {
 				match c.as_full_client() {
 					Some(c) => c.transact_contract(a, d)

ethcore/src/engines/validator_set/multi.rs

@@ -138,7 +138,7 @@ impl ValidatorSet for Multi {
 		}
 		*self.block_number.write() = Box::new(move |id| client
 			.upgrade()
-			.ok_or("No client!".into())
+			.ok_or_else(|| "No client!".into())
 			.and_then(|c| c.block_number(id).ok_or("Unknown block".into())));
 	}
 }

ethcore/src/engines/validator_set/safe_contract.rs

@@ -311,7 +311,7 @@ impl ValidatorSet for ValidatorSafeContract {
 		let client = self.client.read().clone();
 		Box::new(move |addr, data| client.as_ref()
 			.and_then(Weak::upgrade)
-			.ok_or("No client!".into())
+			.ok_or_else(|| "No client!".into())
 			.and_then(|c| {
 				match c.as_full_client() {
 					Some(c) => c.call_contract(id, addr, data),